1. Field of the Invention
The present invention relates generally to an apparatus for dyeing tissues sampled from a living body for the purpose of observing immunoreaction of the tissues, e.g., in the case where an examination for cancer is performed in hospitals.
2. Description of the Related Arts
In order to diagnose diseases such as cancer, commonly utilized are immunoreaction such an antigen antibody reaction. For the diagnosis of diseases making use of such immunoreaction, pieces of tissue sampled from a living body are attached to glass slides and brought into contact with predetermined dyeing liquids in turn to dye the pieces of tissue.
Conventionally, when performing a dyeing treatment with the aim of observing the immunoreaction, dyeing solutions or liquids are prepared in beaker-like containers, and glass slides to which pieces of tissue are respectively attached are immersed in the dyeing liquid in these containers, thereby bringing the pieces of tissue into contact with the dyeing liquids. This inevitably results in an increase in the volume of the dyeing liquids used. Since most of the dyeing liquids used for the observation of the immunoreaction are expensive, the increase of the amount of the dyeing liquid used is not desirable.
Conventionally, the dyeing operation of the tissues is often manually performed to reduce the treating cost, which is however a time-consuming work and sometimes requires an all-night operation. This is not desirable in terms of the working condition of the workers.
In order to overcome these problems, there has been proposed a tissue dyeing apparatus capable of carrying out an operation of dyeing tissues with a small amount of dyeing liquids (U.S. Pat. No. 5,068,092 to Toya, issued Nov. 26, 1991).
The tissue dyeing apparatus disclosed in this U.S. patent comprises a dyeing block on which a row of rectangular plateaus are formed. The plateaus have flat upper surfaces, respectively. On both sides of the row of plateaus are provided raised supporting surfaces for supporting thereon glass slides in such a manner that the slides are positioned above the plateaus with wedge-shaped capillary gaps formed between the upper surfaces of the plateaus and the undersurfaces of the slides, respectively. Each plateaus has a width greater than the width of the associated slide so that the upper surface of each plateau is exposed on both sides of the associated slide.
A dyeing liquid is dripped from above onto the exposed portion of the upper surface of each plateau. The thus dripped dyeing liquid spreads into the wedge-shaped gap under the slide by virtue of the capillarity and acts on the piece of tissue attached to the undersurface of the slide to dye the piece. After the dyeing operation, the used dyeing liquid is sucked through a liquid discharge port formed on the upper surface of the plateau and is sent to a waste liquid tank.
Thereafter, a cleaning liquid is supplied into the wedge-shaped gap through a cleaning liquid supply port formed on the upper surface of the plateau, for cleaning or rinsing to remove the remaining dyeing liquid. After that, another dyeing liquid is supplied into the gap in the same way as stated above and the same operation as above is repeated.
In the known tissue dyeing apparatus described above, each plateau must be larger in width than the slide to provide a dyeing liquid dripping surface on the plateau, so that the plateaus occupy a relatively large space and the dyeing block becomes bulky for the number of slides that can be accommodated on the dyeing block.
Furthermore, in the known tissue dyeing apparatus, the liquid discharge port and the cleaning liquid supply port are connected to a liquid discharge pipe and a cleaning liquid supply pipe at the lower surface of the dyeing block so that the dyeing block cannot be used for manual dyeing and cleaning operation.